Non-Hermitian and Liouvillian skin effects in magnetic systems
Phys. Rev. B 112, 134416 – Published 8 October, 2025
DOI: https://doi.org/10.1103/6msp-vbbm
Abstract
The non-Hermitian skin effect (NHSE) has emerged as a hallmark of non-Hermitian physics, with far-reaching implications for transport, topology, and sensing. While recent works have uncovered the NHSE in magnetic systems, these analyses rely on effective non-Hermitian Hamiltonians, thereby leaving open critical questions regarding their applicability and predictive power in experimentally feasible platforms. Here, we address this gap by exploring both the non-Hermitian and Liouvillian dynamics of a spin chain coupled to a shared bosonic reservoir. We identify the parameter regime in which these frameworks yield congruent predictions, while showing that the non-Hermitian approach fails to capture essential dynamical features—such as relevant timescales and conditions for experimental observability. Our analysis also reveals that the NHSE stems from the interplay between chiral spin couplings and reciprocal nonlocal dissipation—two interactions that can naturally occur in magnetic crystals and be easily engineered in magnetic heterostructures. Focusing on a concrete example of such heterostructures, we establish an explicit connection between their Landau-Lifshitz-Gilbert dynamics and our microscopic model, providing a tangible route toward realizing the NHSE in an experimentally relevant spintronics setup.
